MacGyver - Second AC unit

pconroy · 06-14-2017, 01:35 PM

Whelp, it didn't go as well as I had planned. Our '16 Greyhawk has one 15.5K AC unit and we bake in the summer sun.

I had a MacGyver, or perhaps Rube Goldberg, inspired thought and picked up a gently used portable AC unit. My thought was it was about 9 amps, and 10K BTU, it might help.

The results of prototype #1 were a bit disappointing. Venting the hot air from the back of the AC unit is the biggest challenge. The LG unit I grabbed uses a ducting size that must be 5.99999999" inches. Whatever it is, a standard 6" duct won't fit.

I was able to duct tape up the prototype and route the exhaust out of the bathroom vent. It worked, but I noticed the vent pipe got very warm as well. Clearly part of the prototype was leaking heat back into the cabin.

Toss in the fact that it looked pretty awful - having 4" dryer hose looped around and over the bathroom door was outright impractical.

Prototype #1 is on the shelf.
Back to the drawing board.

Anyone want a portable LG AC unit with a 5.99999999" exhaust port?

PonyExpress · 06-14-2017, 01:45 PM

how hot is it getting. How big it you RV?

have you tried all the other things like the reflectix on the windows and the skylite pillows? are you sure you a/c is functioning properly?

Jopopsy · 06-14-2017, 01:47 PM

That's awesome !!!

Have you tried those solar window covers I mentioned in a earlier post? They really do seem to help.

che57vy · 06-14-2017, 03:32 PM

block off the front cab area, I used the bubble foil insulation cut panels for windshield and side windows blocked cab area with a huge quilt then insulated vents, the dome in the shower lets a lot of heat in. That seemed to work next will make so covers for windows if need be

Jopopsy · 06-15-2017, 06:23 AM

I also strung up a thermal curtain to block off the cab area.

t18skyguy · 06-15-2017, 08:45 PM

I'm just thinking out loud. I don't suppose it's pre-wired for a second air conditioner. I wonder if Jayco would give you the wiring schematics, and even if they did, would you even be able to run the wires. The two on my Greyhawk are 1100 watts each. Was thinking if you were able to put one of those up there you'd be at 2600 watts. It would be great to make it work somehow.

Hivoltage98 · 06-17-2017, 09:01 PM

Second AC retrofit.

https://r.tapatalk.com/shareLink?sha...9&share_type=t

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t18skyguy · 06-17-2017, 09:32 PM

Very cool(no pun intended). Just shows where there's a will there's a way.

pconroy · 06-18-2017, 11:20 AM

Quote:

Originally Posted by Jopopsy

That's awesome !!!

Have you tried those solar window covers I mentioned in a earlier post? They really do seem to help.

Last weekend was the first chance to try some extra covers on the windows. And, yes they did help!

It still got warm in there, but I think it knocked the temps down by 5*, maybe. But it seemed to be an improvement. A July/August test will tell us for sure.

connjab · 06-18-2017, 12:39 PM

we had that issue in a tt and got lots of improvement by putting a fan in the hallway and blowing cool air to the back bedroom. Worked great for us. Could also put small fan in bedroom to move air around. You don,t need a big one because of the small area in the bedroom. Good luck.

drk98 · 06-18-2017, 09:25 PM

Being in the Houston area this weekend, I'm really glad we installed the 2nd AC in our redhawk.

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goldenbetty · 06-25-2017, 06:57 PM

How do the two 11's cool in the summertime? We are in the planning stages for a Jayco Greyhawk 29MV. Honest opinion please.

t18skyguy · 06-26-2017, 08:50 AM

My Greyhawk with the two 1100's work very well. It was 100 degrees yesterday and I was completely comfortable. The fact that it's ducted is a big plus cause it distributes the cool air evenly. On youtube, there is a video by an RV salesman called something like "Top 10 Mistakes made when buying an RV" Not getting a second air conditioner in a larger rig is right up there on the list. When I have one on it draws just 7 amps. I would say the force of the cool air coming out is about at least 80% of what my old 1500 watt would do, but the two handle it nicely.

goldenbetty · 06-27-2017, 01:14 PM

Thank you for the reply. The A/C situation is our prime concern. This will be our first motorhome. We are really excited about the thought of an "easier" setup than with our fifthwheel. We just want to make sure that we can keep it cool enough in the hot summers down south. Have you had experience with running both airs on the generator when dry camping?

t18skyguy · 06-27-2017, 11:46 PM

I have only owned mine a couple month's, so have not tried them on the genny. That being said, I believe they are sized to do a good job and also be able to use the microwave also. Two AC's 2200 watts plus microwave 1200? would put it at 3400 watts. The 4000 watt genny should be able to handle it I think if you start them one at a time. I'm not an electrician, maybe those guys could chime in. But I'll tell you what I'll do. In the morning, I'll fire up the genny, put on both air conditioners, and the microwave, and I'll report back the results.

t18skyguy · 06-28-2017, 12:14 PM

I tested the genny this morning with both air conditioners running plus the microwave. This is on my 2017 31FS. The first thing I did was scroll the digital amp gauge to the 30 Amp service. Then I turned on the genny and with one air conditioner on it read out 7 amps. With two air conditioners on gave 14 amps. With both air conditioners I then put some water in the microwave and fired it up and the amp gauge read 24 amps. With all three of those units the genny was working a bit, but was not bogging down or strained at all. So as to your original question, two 1100 watt air conditioners don't phase it at all. It appears the microwave is 10 amps according to the gauge. I probably could have added the frig to see where it would be then, but that's for another time. My feeling is the rig is designed well to be supported by the genny.

PonyExpress · 06-28-2017, 01:15 PM

what you need to test is having an a/c running, the micro running and then have the other a/c start up. Thats where your likely to have an issue

rgolding · 06-28-2017, 02:39 PM

We have a BLACK Seneca 37FS. We live in it in Florida in the Winter, but 95 degrees and in the Summer at Rodeos with absolutely no shade. We have 2 air conditioners, which were standard, but seldom use the bigger 15,000 in the main cabin. We keep all shades pulled down in the heat of the day and use reflective inside window coverings over the windshield and side truck cab door windows. Besides that, we use the insulated vent cover in the bathroom and experimented with shower bubble cover in previous TT, but haven't found the right size for this one, yet. Recommend you try a big quilt closing off the whole truck cab during the heat of the day. Its like a giant heat sink and when closed off, you'll be amazed at how hot it gets up there. Also recommend the small fan. We have 10 inch fan called a tornado and it does make it cooler. Face it forward during the day and toward the back at night. We use that fan also a lot of times to distribute the heat. Just my thoughts, hope it helps.

t18skyguy · 06-28-2017, 03:37 PM

Quote:

Originally Posted by PonyExpress

what you need to test is having an a/c running, the micro running and then have the other a/c start up. Thats where your likely to have an issue

Pony I'll give that a try tomorrow and see what happens

t18skyguy · 06-28-2017, 10:01 PM

Here are the results of my load testing of the genny in my 2017 31FS;adding load one by one on top of the others.

First AC 7amps
Microwave 18 amps total
AC#2 24 amps total
Refer on AC went to 27 amps total

The genny was working, but not straining or bogging. So far am happy with what I see.

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